checkNotNull(keyFunction);
    checkNotNull(valuesFunction);
    return collectingAndThen(
        flatteningToMultimap(
            input -> checkNotNull(keyFunction.apply(input)),
            input -> valuesFunction.apply(input).peek(Preconditions::checkNotNull),
            MultimapBuilder.linkedHashKeys().arrayListValues()::<K, V>build),
        ImmutableListMultimap::copyOf);
  }

  }

  private static void testReverse(int[] input, int[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Ints.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(int[] input, int fromIndex, int toIndex, int[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Ints.reverse(input, fromIndex, toIndex);

  }

  private static void testReverse(byte[] input, byte[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Bytes.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(byte[] input, int fromIndex, int toIndex, byte[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Bytes.reverse(input, fromIndex, toIndex);

    input.put("foo", 1);
    input.put("bar", 2);
    input.put("foo", 3);
    input.put("foo", 1);
    Multimap<String, Integer> multimap = ImmutableListMultimap.copyOf(input);
    assertEquals(multimap, input);
    assertEquals(input, multimap);
  }

  public void testCopyOfEmpty() {
    ArrayListMultimap<String, Integer> input = ArrayListMultimap.create();

  }

  private static void testReverse(int[] input, int[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Ints.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(int[] input, int fromIndex, int toIndex, int[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Ints.reverse(input, fromIndex, toIndex);

  }

  private static void testReverse(char[] input, char[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Chars.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(char[] input, int fromIndex, int toIndex, char[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Chars.reverse(input, fromIndex, toIndex);

  private static void testReverse(short[] input, short[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Shorts.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(
      short[] input, int fromIndex, int toIndex, short[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Shorts.reverse(input, fromIndex, toIndex);

    // below. Allocate enough space so that no reallocation happens, which will
    // make the pointers invalid.
    all_input_tensors.reserve(num_inputs);
    for (int i = 0; i < num_inputs; ++i) {
      if (input_tensors[i] == nullptr) continue;
      all_input_tensors.emplace_back();
      Tensor& input_tensor = all_input_tensors.back();
      status->status = TF_TensorToTensor(input_tensors[i], &input_tensor);

  private static void testReverse(double[] input, double[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Doubles.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(
      double[] input, int fromIndex, int toIndex, double[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Doubles.reverse(input, fromIndex, toIndex);

  private static void testReverse(double[] input, double[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Doubles.reverse(input);
    assertThat(input).isEqualTo(expectedOutput);
  }

  private static void testReverse(
      double[] input, int fromIndex, int toIndex, double[] expectedOutput) {
    input = Arrays.copyOf(input, input.length);
    Doubles.reverse(input, fromIndex, toIndex);